IL6 and rheumatoid arthritis: While a few reports have used proteomic analysis [23,24], genome micro-array[25] and serum markers including several cytokines[26], to identify biomarkers to predict treatment outcome to anti-TNF-α therapy, only two recent reports have identified biomarkers to predict RA outcome to anti-IL-6 therapy using sIL-6R levels [27] or genome micro-array [28].